Automated analyzers have been developed for biochemical analysis of patient samples, such as whole blood, serum, urine, plasma and cerebral spinal fluid. Most such equipment available today is complicated to operate, large in size and high in cost.
The operation of such equipment is technically complicated. It typically requires specialized operators to be available at all times, with commensurate personnel expenses being encountered. It is usually designed for use by large laboratories serving a wide geographic area or by a large medical facility. These existing analyzers carry out tests in a defined sequence of operations designed for efficient, high volume usage.
Such large scale capacity is not always required, particularly in smaller medical clinics where large volumes of blood samples are not encountered on a daily basis. The present chemical analyzer was developed to meet the practical needs of smaller medical settings. It is designed as a desk-top unit that can be operated without specialized laboratory training. Its throughput is adequate for meeting typical clinical applications.
The compact nature of the analyzer can be partially attributed to the fact that a single probe arm and pipette service all of the functional liquid-handling components included within it. The common pipette is used for transferring samples and reagents, as well as for diluting liquids as needed by particular test requirements.
To obtain large volumes of tests, conventional laboratory analyzers are programmed to conduct test procedures in a fixed sequence of events. While predetermined test sequences are practical in high volume chemical analyzer applications, there is a need for more flexible operation when sealing such test procedures to meet the needs of smaller medical facilities.
The present invention provides testing flexibility by permitting random access to each cuvette on a test turntable. It is therefore not necessary for the instrument to sequence through any predetermined processing steps-the controlling software can tailor the required steps to the tests currently requisitioned. This permits a greater number of tests to be conducted while using a minimum number of containers, cuvettes and reagent bottles. The software controls the sequencing of tests based upon predetermined priority schedules, rather than defined test sequences dictated by the nature of the tests being conducted.
Increased versatility is also provided in the present chemical analyzer by providing the capability of inserting pre-loaded reagents within cuvettes fed to a dispensing magazine that directs them to the turntable. Flexibility is further enhanced by providing random access to a plurality of stacks of incoming cuvettes, some of which can be preloaded and some of which can be empty. This provides the capability of random access to prepackaged chemistry involving powdered or solid reagents to supplement the liquid reagents available on the sample/reagent tray.
Disposable cuvettes are provided automatically within the analyzer by a cuvette dispenser. Reloading of the cuvettes into a dispensing magazine included in the chemistry instrument is physically organized to meet the supply needs of the instrument with minimum cuvette handling by the operator.
A reaction turntable is capable of handling a maximum of 48 cuvettes at any given time. Both absorbance and fluorescence polarization tests can be carried out with respect to selected cuvettes through use of a single optical system.
Further details concerning the system will be evident from the following description.